Secondary disazo dyes



Patented Aug. 23, 1932 'rsr is WERNER LANGE AND MAX RAECK, OF DESSAU-ZIEBIGK IN ANHALT, GERMANY, AS-

SIGNORS 130 GENERAL ANILINE WORKS, INC., NEW YORK, N. Y., .A. CORPORATION or DELAWARE SECONDARY DISAZO DYES No Drawing. Application filed April 23, 1931, Serial No. 532,390, and in Germany May 28, 1930.

Our present invention relates to a new process of manufacturing secondary disazo dyes. One or" its objects is a method to provide dyes of this kind dyeing regenerated cellulose bright and even tints.

Additional objects are the new dyes obtain This invention is based onthe observation that nearly all dyes ofthe said classes have a certain levelling power on regenerated cellulose. But those dyes are distinguishedby a perfectly clear tint and aboveall by a good tastness to light and a good levelling power on artificial silk tending to be dyed unevenly, which contain as middle component a 1.4-diamino-sulfonic acid of the benzene series and I as end components amino, alkylamino or arylamino derivatives of the benzene or naphtha. lene serles which, after coupling, can no longer be diazotized, the azo group entering in ortho-position to the free or substituted amino group or in para-position to the sub stituted amino group, and of which at least one end component is a 2-amino-, 2-alkylamino-, or 2-.arylamino-8-hydroxynaphthalene-S-sultonic acid coupled in an acid medium.

Thus, our new dyes may be represented by the general formula reddish-blue to greenish-blue.

wherein It means a substituted or "unsubstituted amino compound of the benzene or naphthalene series, wherein the benzene nucleus of the middle component may be substituted and wherein X means H, alkyl orf- '55 aryl. r V

The shades obtainable with these dyes are All of the dyes are considerably faster to light thanthe analogous dyes with end components, whicht are coupled in orthoor para-position to a hydroxyl group. i This effect could not be seen or derivedfrom the specification above referred to. l The observation on which the process claimed is based, shows a quite new, unexpected and, at the same time, important technical progress, since, blue dyes of this clarity of tint and a fast-ness to light, which approaches that of the best substantiveblue dyes of commerce, have hitherto been unknown for regenerated cellulose.

The following examples illustrate the invention, the parts being by weight:

Ewample 1.The diazo compound prepared in known manner from 21.8 parts ef 1-amino-mitro-benzene-Q-sulfonic acid is introduced into an acid suspension of 23.9 parts of 2-amino-8-hydroxynaphthalene-6-sulfonic acid, which has been made by dissolving the acid with sodium carbonate in water and precipitating with acetic acid, and the whole is stirred, while adding an excess of sodium acetate, until the diazo compound has disappeared. The mass is then rendered alkaline A by means of sodium hydroxide, heated to 60 c C. and, after addition of about 15 parts of sodium sulfide, stirred until the nitro com-, pound has been transformed into the amino compound which is precipitated by addition of sodium chloride. The amino-azo dye is dissolved in about 1000 parts of water and diazotized in the usual manner, whilecooling, with hydrochloric acid and about 5 parts of sodium nitrite; then a suspension of 2- amino-8-hydroxynaphth alene-6-sulf0nic acid in acetic acid in an amount calculated upon the consumption of sodium nitrite during the second diazotization and prepared as r above indicated, and sodium acetate are added thereto and the whole is stirred until the diazo compound can no longer be detected. The product is then rendered alkaline by means of sodium carbonate and the disazo dye is separated by means of sodium chloride; it

is purified by dissolving in water and again salting out in the presence of an alkali.

Thedye dyes cellulose regenerated from viscose and cotton very vivid greenish-blue V tints of good fastness to light.

. As free acid it corresponds to the formula 03H soiH By using for the second development in stead of the 2-amino-8-hydroxynaphthalene 6-sulfonic; acid a corresponding'quality of 2- methylamino-naphthalene-7-sulfonic" acid, a

very similar dye is obtained Example 2.26 parts of 1-methoxy-2 acetylamino-5-aminobenzene--sulfonic acid whole is stirred until the diazo compound has disappeared. Then-so much of sodium hydroXide is added "that, after neutralization,

2% thereof is contained in the liquid, and the i whole is boiled for hours in a reflux apparatus. After neutralization of the excess of alkali with hydrochloric acid, the dye is precipitated by addition of sodium chloride and separated fromtheliquid. The dye is redissolved in about 1000 parts of water an diazotiz ed in the cold, as usual, with hydrochloric. acid and. sodium nitrite. Then a susdisappeared.

' pension of 23.7 parts of 2-methylaminonaph- '7 thalene-Y-sulfonic acid, prepared by dissolv ing the acid in sodium carbonate solution and acidifying withacetic acid, an excess of sodium acetate are added thereto. The whole is again'stirred untilthe diazo compound has It is then rendered alkalinewith sodium carbonate and'filtered by suetionwithout addition ofsalt. The dye can be purified by mixing it with water and again filtering bysuction. It dyes cotton and cellulose regenerated from viscose uniform ,greenish-blue tints. I A X fastness to light.

As free acid it corresponds to the formula Example 3. 26 parts of -amino-2-acetylamino-1-methoxybenzene d-sulfonic acid are diazotized in an aqueous suspension at 5 (L-8 Q'with 22 parts of hydrochloric acid of B. and 6.9.parts'of sodium nitrite. Into this diazotized mixture are introduced 25 parts of 2-amino-8'-hydroxynaphthalene- 6-sulfonic acid suspended in dilute acetic acid. An excess of sodium acetate is added thereto and the mixture is stirred until the couplingis complete. The separated mono azo dye is filtered by suction and heated for about 1 hour to 90 C. with 1200 parts of a 1% sodium'hydroxide solution. The dye is then isolated, dissolved in water and further diazotized in the usual manner. the diazotized solution 25' parts of 2-methylamino 8 hydroxynaphthalene 6 sulfonic acid suspended in dilute acetic acid,are entered. After the couplmg 1s complete, the

dye is filtered by suction and dried. The dye" dissolves in water to a clear greenish-blue solution and dyesviscose artificial silk an even, very clear greenish-blue tint of good As free acid it corresponds to the formula EwampZe 4.-Themonoazo dye obtainable Into according to the first step described in the foregoing example, is diazotized after saponification of the acetylamino group and 22 parts of 2-amino-8-hydroxynaphthalene-6- sulfonic acid suspended in dilute acetic acid are added to the diazo compound. After" the manner described a disaZo dyeis produced corresponding to the formula OaH SOaH 'working up the reaction product obtained in V 7 It dyes viscose silk clear green-blue tints, V V

greener than that obtainable according to Example 1. V v Example 5.26 parts of amino-l-methoxybenzene--sulfonic acid are combined in an acetic acid solution with 2- amino-8-hydroxynaphthalene-6-sulfonic acid as described in Example 3. The acetyl group is split off, the monoazo dye is further diazotized and combined with 2-n. butylami-- no-naphthalene-7-sulfonic acid in the presence of sodium carbonate. The dye 1s worked up in the usual manner. It dissolves in water to a blue solution and dyes vlscose artificial silk an even, clear blue tint of good fastness to light.

As free acid it corresponds to the formula Example 6.The monoazodye obtainable according to Example 5 is coupled, instead of with 2-11. butylamino-naphthalene-7-sulfonic acid, with dimethylaniline in an acetic acid solution. A dye is obtained which dissolves in water to a blue solution and dyes viscose artificial silk an even, blue tint of good fastness to light.

As free acid it corresponds to the formula 00113 N H2 OHa S 0 3H H O 90311 What we claim is 1. The new secondary disazo dyes corresponding as free acids to the general formula wherein R means the radicle of an amino compound of the benzene or naphthalene series which can no longer be diazotized, Y stands for H or OCT-l and wherein X means H, alkyl or phenyl, these dyes dyeing artificial viscose silk bright, clear and even reddish-' blue to greenish-blue tints of excellent fastness to light.

2. The new secondary disazo dyes corre-;

sponding as free acids to the general formula Y NHz wherein R means the radicle of an alkylated aniline or a ,B-naphthylamine compound, Y

sponding as free acid to the formula wherein Z NQ stands for 'H orOCH coupling the: diazo 311 I V wherein X means, H. or methylandY stands for H or. OCIL, these dyes dyeing artificial viscose silk bright, clear and even greenishblue tints of excellent fastness to light.

4. The new secondary disazo dye corresponding as free acid to the formula SOaH this dye dyeing artificial viscose silk bright, clear and even greenish-blue tints of eXcellent fastness to light.

5. The new secondary disazo dye corre-- sponding as free acid to the formula 03H this dye dyeing artificial viscose silk bright, clear and evengreenish-blue tints of excellent fastncss to light. 2

6. The new secondary disazo dye corre- NHz oorn- N11 011 SOzH HO- L soQH \SOQH this dye dyeing artificial viscose silk bright,

Clear and even greenish-blue tints of excellent fastnessto light. 1,120

7. The process whichcomprises diazotizing a compound of the general formula soar;

or .NH-acyl, and Y compound formed in an acidfmedium with 3.

-",B-aminooxynaph.thalene compound of the general formula V ITTHX Hogs wherein Xmeans alkyl or phenyl, converting Z into the amino group, diazotizing the latter and coupling it with an amino compound of the group consisting of aminobenzenes and aminonap'hthalenes which after formation of the dye can no longer be diazotized.

8. The process which comprises diazotizing a compound-of the general formula whereinmeans N0 or NH-acyh and 'Y stands for or OCH coupling the diazo compound formed in an acid medium with a fl-aminooxy'naphthalene compound of the general formula --NHX 1103s 7 wherein X means alkyl or ,phenyl, converting Z into the amino group, diazotizing the latter and coupling it with an amino compound of the group consisting of alkylated anilines and fl-naphthylamines.

9. The process which comprises diazotizing a compound of the general formula wherein means N0 or NH-acyl,and

stands for H or OCH' coupling the diazo compound formed in anacidmedium witha ,8-aminooxynaphthalene compound of the general formula HOaS wherein X means alkyl or phenyl, converting Z intothe amino group, diazotizing the latter and coupling it with an amino compound likewise 1n an acid medium with a Q-amino- 8-hydroxynaphthalene-6 sulfonic acid.

mono azo-dye into the amino group, diazotizing the latter and coupling it again with 2- .amino-8-hydroxynaphthalene 6-sulfonie acid (in an acidmediuin. r i 1 ing 1 1. The process which comprises diazotiz- 5-amino-2-"acetylamino-1 -methoxybenzenel-sulfonic acid,'coupling the diazo compound in an acid medium with 2-amino-8-hydroxynaphthalene 6-sulfonic acid, saponifying the acetyl-amino group of the monoazo' V dye obtained, diazotizing the amino dye obtained and coupling it with 2-1nethyla1nino-8- hydroxynaphthalene-6-su1fonic acid in an acidmedium; A

12. The process which comprises diazotiz- 11w zeiiel-sulfonic acid,-coup'ling the diazo com pound in an acid medium with 2-amino-8-hydroXynaphthal-ene-6-sulfonic acid, saponify- 7 ing the acetylamino group of the monoazo dye obtained, diazotizing the amino dye obtained and coupling it with 2-amino-8-hydroxynaphthalene-G-sulfonic acid in an acid medium.

In testimony whereof, we aflix our signatures'. a j

WERNER LANGE. MAX RAECK.

5-amino- 2-acetylamino-1 inethoxyben- 

